ES2219930T3 - SYSTEM TO CONTROL THE ACCESS AUTHORIZATION. - Google Patents

Abstract

System for controlling access authorization: - with a base device (BG) that receives a code word (CWx) containing an answer (Rx) that a computer (16) compares with a theoretical response (Sx), so that an access authorization is carried out when the response (Rx) and the theoretical response (Sx) coincide, - with at least one remote control (F1, ..., Fx, ... Fn) that sends the word ( CWx) code, characterized in that at least one remote control (F1, ..., Fx, ... Fn) is stored, to generate the code word (CWx), a stimulus signal (Cx) sent by the base device (BG) within the framework of a stimulus-response procedure already performed successfully in the past

Description

System to control the authorization of access.

State of the art

The invention starts from a system to control access authorization, according to the generic concept of the independent claim. From document DE 44 28 947 C1 a closing device is already known for a vehicle with a activation device, as well as with a transponder. Activating an issuer can generate a change code word for a remote drive, which is received by a device decoding, compared to a change code signal of a remote drive stored in the device decoding and generates an unlock signal based on the comparison. In addition, to increase security, a transponder whose exchange code signal is valued additionally for an unlock.

From DE 195 01 004 A1 it is known a procedure to put into operation a system of data transmission consisting of a transponder and a device reading. For verifiable data transmission between a device reading and a transponder, the reading device sends after its activation of a message - reading device. Upon activation, the transponder receives the message - reading device and transmits a First message - transponder to the reading device. The process of verification is carried out by means of a fixed code - transponder stored in the transponder and a fixed code - device reading stored in the reading device. After authentication  satisfactory between the transponder and the reading device can  the control devices connected to the control unit must be unlocked Reading through communication lines.

The invention is based on the task of simplifying the system of document DE 44 28 947 C1 without suffering a loss of security. The task is solved by the features significant of the independent claim.

The system according to the invention to control the access authorization comprises a base device that receives a code word The code word contains an answer (Response) that a computer compares with a theoretical response (Sollresponse). When the answer and the theoretical answer coincide produces an access authorization. At least one remote control Send the code word. The system according to the invention is characterized because, to generate the code word in the command to distance a stimulus signal is stored (challenge signal) sent by the base apparatus within the framework of a procedure of stimulus - response (challenge - response) already successfully completed in last. Therefore, the challenge signal provides a indication of a remote control authorization. With that Handling possibilities are limited. In addition, it is no longer a new two-way challenge procedure is necessary - response to initiate an access authorization procedure since the challenge signal is already stored in the memory of the remote control. In this way, the word of code to the base device with a greater range, while the challenge procedure - response can only be done in the nearby area This guarantees a decoupling between the bidirectional data transmission and unidirectional transmission of data. Only one transmitter is provided on the remote control greater scope, not, however, a corresponding receiver for the distant area The challenge signal can be used for synchronization of the remote control and the base unit. Besides, the answer or decisive theoretical answer directly for the access authorization is not stored in the base device, nor on the remote control, such that access is not possible Direct to this information relevant to security.

In a convenient improvement, the answer theoretical is formed based on an indicator stored in the command remote and included in the code word. With it get an unequivocal assignment between the remote used and the corresponding encryption stored in the base device. The unambiguous assignment guarantees sufficient security high against unauthorized manipulation attempts. With that the algorithm that encrypts the remote control the challenge signal stored to give rise to a response, for example, using a specific indicator of remote control, and can be integrated into a microcontroller

In a configuration, after a number default mismatches of the response and the theoretical response, the challenge signal stored in the base device With this, in the case of a number of attempts to failed opening is guaranteed that a access authorization to continue testing. You should only allow one new opening attempt in combination with a procedure of Challenge - Successful response. When the access authorization through the unidirectional protocol, security requirements increase and access can be achieved only in combination with the complex bidirectional protocol.

An advantageous configuration provides that in the code word is contained a counter code that the base device compares with a reference code. Only in case of a divergence takes place an access authorization. The code of  counter is modified by activating an operating element of the remote control. No access authorization is released to the Send the code word that was just intercepted. The state of the counter can be present both encrypted and decrypted in The code word.

A code is used as a reference code sent. A counter function is not provided for this. independent on the base device.

Conveniently, the transmission of the code word takes place at a high frequency and the transmission of the challenge signal, at a low frequency. Because the challenge signal stored, the remote control does not require No receiver in the high frequency range.

Of the other dependent claims and of the descriptive report other improvements are obtained suitable of the invention.

He drew

The drawing shows two examples of possible embodiments of a system according to the invention for control access authorization and are explained in detail in The following descriptive report. Figures 1 and 2 show a block diagram and an access authorization procedure for a first embodiment, figures 3 and 4 show a block diagram and an access authorization procedure for A second embodiment.

Description

Several F1 controls, ... Fx, ... Fn remote communicate with a base BG device comprising a transmitter / receiver 12 and a computer 16. Computer 16 exchanges data with the sender / receiver 12 and has access to signals C1, ... Cx, ... Cn of challenge, indicators K1, ..., Kx, ... Kn and a limit G value stored in memory. As an example, the remote control structure Fx, number x. A computer 20 of remote control has access to the Kx indicator stored in the memory and the Cx challenge signal. It issues data to the issuer 22 e exchange data with a transmitter / receiver 26 of the remote control. The signal state influenced by a handling element 24 is feeds computer 20 of the remote control.

The second embodiment according to the figure 3 differs from the first embodiment according to figure 1 because the base BG device is provided instead of the G value limit, a memory for a code RZ1, ..., RZx, ... RZn of reference. The remote control Fx has an additional field for a counter Zx code.

The mode is explained in detail below. of operation of the exemplary embodiment shown in the figure 1. A K1 indicator is stored in the base BG device, ..., Kx, ..., corresponding Kn for each F1 command, ..., Fx, ... Fn a distance. With this, the base BG device can identify unequivocally each individual Fx remote control or each Fx group of remote controls, if, for example, a Kx indicator is assigned to several remote Fx controls. These indicators K1, ..., Kx, ... Kn they can be the corresponding memory spaces or recognized through memory space. In the challenge procedure - response, the base unit sends the challenge signal Cx to the command Fx distance assigned unequivocally by means of the Kx indicator. A random number generator generates this Cx challenge signal. Computer 16 stores the challenge signal Cx sent in a memory space addressed by means of the Kx indicator. The remote control computer 20 stores the signal in a memory Challenge Cx sent last by the base BG device.

The user initiates unidirectional communication of the remote Fx control with the base BG device by operating the operating element 24, step 101. The computer 20 of the remote control distance combines the challenge Cx signal stored in memory with an algorithm using specific information from the command to distance for the special remote control Fx, from which response Rx is generated. As specific information of the remote control uses, for example, a part of the indicator Kx, a manufacturer code permanently stored in the remote Remote Fx. However, it is essential that the encryption of the Cx challenge signal, that is, the algorithm and information specific to the remote control, also know and be stored in the base BG device for each remote Fx control. In the code word CWx are included the indicator Kx and the Rx response, if applicable, corresponding instructions from wake up and action. The sender 22 sends the code word CWx to the BG base device, step 103. Computer 16 filters the Kx indicator to from the CWx word of received code. Computer 16 chooses the challenge Cx signal and the encryption addressed with this Kx indicator, with which the Rx response has also been determined on the remote control Fx. From the challenge signal Cx, the algorithm and the specific information of the remote control, is that is, the encryption, stored in the base BG device, the computer 16 calculates the theoretical response Sx, step 105. In the BG apparatus The Rx response received and the theoretical Sx response are compared calculated, step 107. If they match, computer 16 provides a corresponding release signal, step 109. In otherwise, query 111 continues on whether the number of attempts M Opening Failure has already exceeded a limit G value predetermined. If this is the case, no attempt at opening further, step 113. In addition, the challenge Cx signal is eliminated stored in the base BG device. Therefore, it can only be achieved an access authorization upon successful completion of the procedure bidirectional challenge - answer, no, however, with the unidirectional protocol described. If the number of attempts M of failed opening has not yet exceeded the limit G value, it Increase the number M, step 115. Next, follow the step 105, which develops as already described.

Stages from 111 increase the security of unidirectional data transmission, although they are not necessarily necessary.

The second embodiment described to below refers to figures 3 and 4. As already mentioned set out for the first embodiment, in the command Fx a distance the challenge signal Cx is stored. In the command Fx a distance is stored a counter Zx code that is incremented when operating the operating element 24. For each remote control Fx the last counter code Zx is stored in the base BG device stored as code RZ1, ..., RZx, ... Reference RZn. After activate the start process by actuating the operating element 24, step 121, the response Rx of according to the first embodiment. The Zx code of counter is increased by one. In the code word CWx is including the code Zx of encrypted counter, in addition to the response Rx and the Kx indicator. Sender 22 sends the code word CWx to sender / receiver 12, step 123. In turn, computer 16 Filter the Kx indicator from the code word CWx received, by means of which it reads the reference RZx code belonging to the remote control Fx, step 125. Then Compare the counter's Zx code with the reference RZx code, step 127. Since in the base BG apparatus it is stored as reference RZx code the last counter Zx code sent, in the case of a proper activation of the remote control Fx the Zx code of the counter and the reference RZx code differ between yes. However, if these coincide, it is interrupted, step 129. No an access authorization takes place. Otherwise, the BG base device determines the theoretical Sx response, as already indicated for the first embodiment, step 131. If not the Rx response and the theoretical Sx response coincide, step 133, then it is interrupted, step 135. Otherwise, it is provides authorization to initiate an opening process, Stage 137

As a second alternative embodiment, the code Zx of the counter is encrypted on the remote control Fx. For determine the reference Rx code, this encryption must stored addressed in the base BG device. For the Zx code of the counter it is only important that it be modified with each remote control Fx drive, without being essential if it is a through a counter function or other algorithm.

Also, the two embodiments can be combine in the sense that, for example, in development according to figure 4, the query is carried out after step 111. With this can further increase security against attempts Opening not authorized.

The challenge procedure - answer no set out in detail takes place preferably in the area close to the space to be entered, for example, from a vehicle, with a frequency less than the transmission of the signal to through the transmitter 22 which allows a greater range. Not planned a corresponding receiver for the remote control Fx. The algorithm to encrypt the challenge Cx signal to get the Rx response, preferably performed so simply that this can also be implemented in a microcontroller.

Claims (9)

1. System to control the authorization of access, - with a base device (BG) that receives a word (CWx) code that contains a response (Rx) that a computer (16) compares with a theoretical response (Sx), so that it leads to Perform an access authorization by matching the response (Rx) and the theoretical answer (Sx), - with at least one remote control (F1, ..., Fx, ... Fn) that sends the code word (CWx), characterized in that at least one remote control (F1, ..., Fx ,. .. Fn) remotely is stored, to generate the code word (CWx), a stimulus signal (Cx) sent by the base device (BG) within the framework of a stimulus-response procedure already performed successfully in the past. 2. System according to claim 1, characterized in that the theoretical response (Sx) is formed as a function of an indicator (K1, ..., Kx, ... Kn) stored in the command (F1, ..., Fx, ... Fn) remote and included in the code word (CWx). 3. System according to one of the preceding claims, characterized in that the stimulus signal (Cx) is stored in the base apparatus (BG). System according to one of the preceding claims, characterized in that the stimulus signal (Cx) stored in the base device (BG) is eliminated when the number of mismatches in the response (Rx) and the theoretical response (Sx) exceeds a value (G) limit that can be set previously. System according to one of the preceding claims, characterized in that a counter code (Zx) is included in the code word (CWx) that the base device (BG) compares with a reference code (RZx). 6. System according to claim 5, characterized in that the counter code (Zx) is modified by operating a remote control operating element (24) (F1, ..., Fx, ... Fn). System according to one of the preceding claims 5 or 6, characterized in that a sent counter code (Zx) is used as the reference code (RZx). System according to one of the preceding claims 5 to 7, characterized in that the counter code (Zx) is included encrypted in the code word (CWx). System according to one of the preceding claims, characterized in that the transmission of the code word (CWx) takes place with a higher frequency than the transmission of the stimulus signal (Cx).